ron_al

Typically, the 43mm measurement refers to the inner portion of the fork leg. In a "right-side-up" fork (as on OEM factory fork on the VFR 800), that inner portion is what is held by the triple clamps (so they are engineered to hold 43mm fork tubes). The larger outer portion is thus at the bottom, and has the brake caliper mounting points & also the axle mounts. In an "upside-down" fork (as in the ebay fork that you posted), that inner 43mm portion is the part that extends to the bottom, and the brake caliper mounts & axle mounts are attached to the 43mm end of the fork. The larger outer portion now extends up to the bike, and is held by the triple clamps. The ebay fork that you posted says that it has 56mm tubes at the bottom triple clamp mounting surface, tapering to 53mm tubes at the top triple clamp mounting surface. So, in order to swap out these forks onto your VFR, you would need a new set of triple clamps, designed to accommodate those larger fork tubes (and that assumes that the fork length is sufficient to maintain appropriate numbers for rake & trail). And as The Phantom pointed out, you would also need to change out the front wheel, axle, brakes, & assorted bits to work with the USD forks. HTH, Ron